Narrow bottom tiltable mast



Ail-8. 1942- H. .1. WOOLSLAYER ETAL 2,293,958

NARROW BOTTOM TILTABLE MAST Filed Aug. 11,1941

' presents a problem because *jcient room between the draw-work's and rear legs "ofthe mast for the driller to stand'at one' end of Patented Aug. 25, 1942 p 2,293,958? v NARROW BOTTOM TILTABLE MAST Homer J. Woolslayer, Erwin A.--Campbell, and

.Cecil Jenkins, Tulsa, Okla., assignors to Lee C. Moore & Company, 1110., Pittsburgh, Pa.; a corporation of Fennsylvania Application August 11, 1941, Serial No 4 Claims. (01. 189-15).

This invention relatesto oil well'masts or derricks, and-more particularly to the general type 'shown' in PatentNo. 2,225,561 to Charles L. Henry.

' 'The-bottom of the ordinary oil'well derrick-or mastfis'relatively wide and the draw-works is located between, its tworear'legs so that the driller, who stands at one end of the draw-works, can operate-the draw-works controls and see up through the mast to the top. A=practical porable mast, on the other hand; should have a relatively narrow bottom so that'it can be readily transported mm one well to another, but this there is not sufiithe draw works, and there even may not be enoughroom for the draweworks itself. Another difliculty with the conventional mast is that it is sometimes desirable or necessary after drilling with rotary equipment to change over'to-reciprocating impact drilling to bring the well in, but in such a case the crown-block first must be changedor its positionshifted in order-to bring the drilling cable into line". with the center of the well because that cable extends down from the periphery of a sheave of the, crown-block while the traveling block that supports the drill stem of the rotary'equipm'ent hangs beneath the axis of the sheave.

It is among the objects of thisllibvention to provide an oil well derrick structure having a narrow bottom which is formed tdaccommodate draw-works of. various sizes and the driller in their customary locations, and which, isrsuitabie for both rotary and impact-drilling without requiring the crown-block to be changed or moved relative to the mast. a

In accordance with this invention a mast, preferably. formed of two-independent complementary overlapping sections of different heights detachabl'y connected together, is mounted on a working platform. The bottomof the mast is relatively narrow and its front legs are hinged to the platform. To permit the draw-works to be mounted in itscustomary' position with room at the endof it for the driller to stand, the lower portions of the rear legs extend rearwardly at an oblique angle to their upper portions so that the downwardly diverging. front and rear sides of the short section of the mast are wide apart at their lower ends with no mast obstruction between them. The draw-works sits in this space beneath the back side of the tall section of the mast. To change from rotary to impact drilling the lower ends of the short sectionsrear legs, which are' pivoted where they join the'tall section of the mast, can be swung forward-and-attache'd to the working platform atpoints nearer the front legs. 101, the lower portions of the rear legsman be made extensible. .In either; case the top ofthe mast is swung forward the amount necessary to bring the impact drillingvline in themast into line with the center of the well.';. If

extra large draw-works ,isbeing used the lower endsof thefshort sectionsrear legs can be swung rearwardlyto. provide more roomv between them and the front legs.

The preferred. embodimentv of the invention is illustrated in the accompanyingdrawing in which Fig.1 is aside view of our derrick structure;

- of the mast.

Fig. 2 is a view. of the derrick from the drawworks side; Fig. 3. is ahorizontal section taken on the line III-III of Fig. 2;. and Fig. 4 is'an enlarged fragmentary sideviewof the connection of the top of the short section to the tall section "Referring to to be slidable along the ground or transportable 1 from one location to another if desired. The

mast is made. in-two independent structure! sections detachably connected together. One of these sections is relatively short and includes the lower portions, 2 of thetwo rearlegs-ofthe mast with suitable bracing members connected thereto. As seen in Fig. 1 these short legs 2 are supported by inclined braces 3 connected to the working platform. The upper ends of the braces 4 3 and legs 2 are pivotally connected together as shown in Fig. 4.

E. The other or tall section of the consists f of the remaining portion thereof and includes the legs.

front legs 4 which are mounted on the working platform, and the upper portions 5 of the rear To help supportand brace these rear legs diagonal braces S are connected thereto and to the lower ends of the front legs. The adjacent ends of the rear legs! and 5 are. connected together in any suitable manner, such as by swinging eye-bolts 'l permanently. connected to the tall section of the mast and detachably connected to --.the top of the short sectionas shown in Fig. 4.

Due to the formation of the mast in. the twoindependent but detachably connected sections" just described it can be erected by fabricating or assembling it along the ground and then raising it to upright position. For this purpose the lower ends of the front legs and braces 3 are detachably Figs. 1 and 2 of the drawing,-the .bottom of an oil well derrickor mast is shown -mountedcn a working platform. I so formed as plication Serial No. 407,923, filed August 22, 1941;

now Patent No. 2,271,578.

The draw-works for the well is shown mounted on the working platform and includes a hoisting drum H which is rotated by suitable engines l2.

up against the mast when the mast is lowered.

A still further feature of the invention is that if it is desired to mean extra large draw-works that would not at between the front and rear legsof the mast, the lower ends of the short rear legs 2 can be swung rearwardly to increase the space between front and rear legs. The rear legs are then fastened to brackets n behind hinges 9.,

According to the provisions of the patent statutes, we have explained the principle and construction of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the, appended claims, the invention may be A cable It extends from the drum up over the crown-block i4 and down into the mast where it suspends directly over the well I! a traveling block It for supporting the drill stem used in rotary drilling.

' It is a feature of this invention that although the bottom of the mast is not much wider than the draw-works, there is plenty of room :for the driller to stand in his usual position atoneend of drum .l Lr'l'his is because the lower portions 2 of the rear legs that form the rear side of the short section ofthe mast extend rearwardly at means hinging the front legs to the platform,

an oblique angle to their upper portions 5 so that those legs are behind the position occupied by the driller which is just about where the rear legs would be if they were straight from top to bottom of the mast as in conventional oil well masts. Our construction givesthe driller a relatively large unobstructed space in which to work.

Another feature'of this invention is that the outwardly extending rearlegs 2 and the hinge connections of the mast'to theplatform permit the mast to be quickly and easily changed from rotary to impact drilling. This is accomplished by tilting the mast forward to the broken line position of Fig. 1 to bring a drilling cable I! (in broken lines) hanging from one of the center sheaves ll of the crown-block'in vertical alignment with the center of the well. For this pur-- pose the working platform is provided with brackets 2| between hinges I and 9 for receiving the lower ends of the rear legs at points a short distance infront of hinges i in which they are normally mounted, when 1egs'2 are swung forward to braclretsil they necessarily swing the entire mast forward. Another way of tilting the mast for this purpose or for merely adjusting'the position of the crown-block relative to the center of the well, is to make the short rear legs 2in two sections so that they can be lengthened.

This can be done in many different ways, the

v drawing showing merely for the purpose of illustration the two sections of each leg detachably connected by plates 22 bolted'through theleg.-

The drilling cable I! extends'down from the crown-block to a bull wheel mounted in front practiced otherwise than as specifically illustrated and dwcribed.

4 We claim:

1. An oil well derrick structure comprising a narrow workingplatform, a mast mounted on the platform, and having front and rear legs,

the lower ends of the rear legs being pivoted relative to their upper portions and being attachedto said platform at points spaced rearwardlyof the plane of said upper portions, and meanson said platform for attaching said rear legs thereto at points closer to the front legs whereby to swing the top of the mast forward.

2. Anoil well derrick structure comprising a narrow working platform. a must moimted on the platform and having front and 'rear legs, means hingin the front legs to the platform, the lower ends of'the rear. legs being pivoted relative to theirupperyportions and being attached to said platform at points spaced rearwardly of the plane of said upper portions to provide adequate working space in the bottom of the mast for draw-works rotary drilling, the lower portions of said rear legs being extensible whereby to swing the, top of the mast forward for impact drilling. a

.3. An oil well derrick structure comprising a narrow workingplatform, a mast mounted on the platform and having frontand rear legs, means hinging the front legs to the platform, the lower ends of the rear legs being pivoted relative to their upper portions and being attached to said platform at points spaced rearwardly of the plane of said upper portions, and means on said platform for attaching said rear legs thereto at points farther from the front legs whereby to provide more space for draw-works between the front and rear legs.- 1

4. An oil well derrick structure comprising a narrow working platform, a mast mounted on the platform and having front and rear legs. the. lower ends of the rear legs being pivoted relative to their upper portions, and means on i said platform for attaching said rear legs thereto at a plurality of predetermined points spaced different distances rearwardly of the plane of said upper portions of the rear legs, whereby to permit the distance between the lower ends of the front and rear legs to be varied.

, Korma J. WOOL-SLAYER.

nawm A. caurnm. cacn. mums. 

